Abstract: The main idea and mathematical treatment of the simultaneous evaluation of14 MeV neutron cross section are described in detail. A simultaneous evaluationof the ~(56)Fe(n, p) ~(56)Mn, ~(27)Al(n, a)~(24)Na, ~(63)Cu(n, 2 n)~(62)Cu, ~(27)Al(n, p)~(27)Mg, ~(41)K(n, p)~(41)Ar cross sections is done and yielded a set of considerably satisfying resultswhich are 109.7, 114.2, 533.5, 71. 8 and 48. 0 mb, with errors (1 σ) 0.88%, 1. 1%,1.5%, 2.0% and 3.2% respectively.